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Convert proc_macro_back_compat lint to an unconditional error.

We still check for the `rental`/`allsorts-rental` crates. But now if
they are detected we just emit a fatal error, instead of emitting a
warning and providing alternative behaviour.

The original "hack" implementing alternative behaviour was added
in #73345.

The lint was added in #83127.

The tracking issue is #83125.

The direct motivation for the change is that providing the alternative
behaviour is interfering with #125174 and follow-on work.
This commit is contained in:
Nicholas Nethercote 2024-05-27 09:00:48 +10:00
parent 3607cee3e7
commit cf0c2c7333
14 changed files with 54 additions and 570 deletions

View file

@ -75,7 +75,6 @@ declare_lint_pass! {
PATTERNS_IN_FNS_WITHOUT_BODY,
PRIVATE_BOUNDS,
PRIVATE_INTERFACES,
PROC_MACRO_BACK_COMPAT,
PROC_MACRO_DERIVE_RESOLUTION_FALLBACK,
PUB_USE_OF_PRIVATE_EXTERN_CRATE,
REDUNDANT_LIFETIMES,
@ -3705,53 +3704,6 @@ declare_lint! {
"detects invalid `#[doc(...)]` attributes",
}
declare_lint! {
/// The `proc_macro_back_compat` lint detects uses of old versions of certain
/// proc-macro crates, which have hardcoded workarounds in the compiler.
///
/// ### Example
///
/// ```rust,ignore (needs-dependency)
///
/// use time_macros_impl::impl_macros;
/// struct Foo;
/// impl_macros!(Foo);
/// ```
///
/// This will produce:
///
/// ```text
/// warning: using an old version of `time-macros-impl`
/// ::: $DIR/group-compat-hack.rs:27:5
/// |
/// LL | impl_macros!(Foo);
/// | ------------------ in this macro invocation
/// |
/// = note: `#[warn(proc_macro_back_compat)]` on by default
/// = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
/// = note: for more information, see issue #83125 <https://github.com/rust-lang/rust/issues/83125>
/// = note: the `time-macros-impl` crate will stop compiling in futures version of Rust. Please update to the latest version of the `time` crate to avoid breakage
/// = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
/// ```
///
/// ### Explanation
///
/// Eventually, the backwards-compatibility hacks present in the compiler will be removed,
/// causing older versions of certain crates to stop compiling.
/// This is a [future-incompatible] lint to ease the transition to an error.
/// See [issue #83125] for more details.
///
/// [issue #83125]: https://github.com/rust-lang/rust/issues/83125
/// [future-incompatible]: ../index.md#future-incompatible-lints
pub PROC_MACRO_BACK_COMPAT,
Deny,
"detects usage of old versions of certain proc-macro crates",
@future_incompatible = FutureIncompatibleInfo {
reason: FutureIncompatibilityReason::FutureReleaseErrorReportInDeps,
reference: "issue #83125 <https://github.com/rust-lang/rust/issues/83125>",
};
}
declare_lint! {
/// The `rust_2021_incompatible_or_patterns` lint detects usage of old versions of or-patterns.
///